Krell FBP200C/which tube pre will sound best


I have a Krell 200C and want to make a jump to tubes in the pre-amp to smooth out the sound. My speakers are B&W-802. Shunyata sidewinder gold power cords, wireworld ecilpse 2 speaker cable. Krell KAV-250 cd. My only concern is I hear alot about upkeep. Need some imput. I listen to jazz, classical music, thanks in advance for any guidance you can offer.
itsalldark
I am currently using a CAT ultimate with Krell FBP 300 driving B&W N802. This Pre and AMP Combo sounded fantastic to me. I use NBS Monitor I cable with one end RCA and the other end XLR specially prepare by NBS.
I just purchased a pair of 250fpb mono's & I asked about this very issue. My dealer said that the Sonic Frontiers Line 3 I am using would not be a problem for my amps. This dealer sold S.F. gear at one time. If anybody hears differently please let me know. Lwin
I have been using a Sonic Frontiers Line 3 with my KSA200s and it's a wonderful combination. Highly recommended. SF Line 3s are going for around $2-2.5K used right now. A great buy. Its nice to use balanced between the two which most pre's don't allow.